This invention relates to devices used to provide a dimming function for ordinary single filament incandescent light bulbs. It is specifically designed to fit into a screw-in light bulb socket such as an Edison-type socket, although, with appropriate modifications, the device may also be utilized in other light bulb sockets of different types.
Screw-in sockets have been in common use for many years and devices designed to control current and/or voltage for dimming light bulbs are also known U.S. Pat. Nos. 3,450,893, 3,818,263 and 3,823,339 each disclose a device which utilizes a diode rectifier sandwiched between a pair of metal disc contacts. In each case, the contacts and rectifier are surrounded by a ring of insulating material which separates the contacts from each other and the socket's outer conductor. The assembly disclosed in these patents is placed in a lamp socket between the center conductor of a light bulb and the bottom conductor of the socket and operates by cutting off the top halves of the AC line current waveform to simultaneously dim the associated bulb, reduce temperature and extend the lifetime of the bulb.
U.S. Pat. No. 4,438,344 to applicants herein discloses a dimming disc for removable installation into an Edison-type socket which includes a switching device allowing the associated rectifier to be either switched into or out of the circuit depending upon how far the light bulb is threaded into the socket. Besides the patents discussed above, the following patents were cited during the prosecution of U.S. Pat. Nos. 4,438,344: 2,158,851 to Ceader, 2,158,862 to Phelps, 2,170,317 to Bussmann, 2,688,669 to Quill, 2,824,183 to Marusco, et al., 3,215,891 to Fritz, et al., 3,818,153 to Arvai and 4,229,680 to Berlin, Jr., et al. These references are believed to be of only general interest to the teachings of the present invention.
The main problem with known light bulb dimming devices is that they operate on the principle of the rectifier which eliminates half of each full wave in alternating current. Thus, these devices dim the associated light bulb by approximately 50 percent. In many applications, such dimming is too great and results in insufficient light being present with the dimming device installed Thus, a need has developed for a light bulb dimming device which is portable in nature, easily installed in an existing Edison-type socket but which dims a light bulb less than 50 percent. It is with these aspects in mind that the present invention was developed.
The present invention relates to an improved light bulb dimming device. A need has developed for a light bulb dimming device which is portable, able to be removably installed within a light socket and which reduces the voltage supplied to the light bulb less than 50 percent. The present invention fulfills these objectives.
The present invention includes the following interrelated aspects and features:
(a) In a first aspect of the present invention, the inventive device includes a housing having insulated periphery and top and bottom portions
(b) Each of the top and bottom portions includes a central opening the rethrough exposing contact structure within the housing The top portion opening exposes an electrically conductive contact and the bottom portion opening exposes another electrically conductive contact, which contacts are separated by an insulated space r of annular form defining, along with said contacts, a central chamber.
(c) Within the central chamber is located a silicon bilateral voltage triggered switch having a thickness slightly less than the distance between the electrically conductive contacts. In the preferred embodiment, the switch rests upon the lower contact and has an upper surface slightly spaced from the upper contact.
(d) The upper and lower electrically conductive contacts are specifically designed to be flexible so that when a light bulb is screwed into the associated socket, these contacts may flex sufficiently to enable the upper and lower conductive surfaces of the switch to be serially included in an electrical circuit including a source of alternating current power
(e ) The silicon bilateral voltage triggered switch is specifically designed to allow a lesser amount of voltage out than is inputted therein. In the preferred embodiment of the present invention, the voltage which the switch allows to be applied against the light bulb is reduced to 85 percent of the input line voltage.
(f) Mounted on top of the top portion of the housing is an annulus made of a resilient foam material and preferably having an adhesive on its upper and lower surfaces so that it may adhere both to the top portion of the housing and to the undersurface of the associated light bulb in surrounding relation to the central terminal thereof to facilitate installation.
Accordingly, it is a first object of the present invention to provide an improved light bulb life extender device
It is a further object of the present invention to provide such an improved light bulb life extender device including circuitry designed to reduce the voltage applied to the associated light bulb by less than 50 percent.
It is a still further object of the present invention to provide an improved such device of dimensions small enough to facilitate the easy mounting of the device within a typical light bulb socket.
These and other objects, aspects and features of the present invention will be better understood from the following detailed description of the preferred embodiments when read in conjunction with the appended drawing figures.